In reply to cuppatea: Breathing in a fine powder isn't generally recommended.

Inhaling chalk dust probably isn't a great idea but I don't think you will be inhaling much. You'd want an aerodynamic particle size of less than about 5um for deep lung penetration, anything else will get cleared out pretty effectively or just get swallowed. I am not convinced chalk dust contains a significant proportion of this very fine particulate matter.

In reply to BolderLicious: I'v still got an open book on whether getting chalk dust under a contact lens was the cause of mystery chemical burns on my cornea! healed completely in 3 days, but alarming and extremely painful - this was the only alkali we could think of I had been in contact with

> (In reply to BolderLicious) its an alkali for a start as well as not being organic. It is not real chalk it is syntetic and has similar affect to smoking in that it dries and shriveles your lungs.

I think if it got to the stage of shrivelling your lungs you would notice.

Most of the long-term problems with inhaling nasty particles are linked with them being insoluble and being difficult to clear (especially if they are too big to be ingested by the cells doing the clearing up). 'Chalk' (light magnesium carbonate) should be pretty soluble, assuming it's pure, but might have little bits of something else in it.

It's slightly basic but not really an alkali. However, (having written a jokey article on 'chalk climbers' lung' for a club magazine so long ago that chalk was still actually controversial) I think it can sometimes set off my asthmatic cough if I breathe too much of it.

Walls take this much more seriously than they used to and usually clear it up and insist on use of chalk balls rather than loose powder. As industrial pollutants go I don't think it's a big worry, but if there's a lurking long-incubation period disease brewing, it's probably going to show any time now!

> (In reply to cuppatea)
> Breathing in a fine powder isn't generally recommended.
>
> Inhaling chalk dust probably isn't a great idea but I don't think you will be inhaling much. You'd want an aerodynamic particle size of less than about 5um for deep lung penetration, anything else will get cleared out pretty effectively or just get swallowed.

You are spot-on, it is the particle size distribution (MMAD) that determines where an airoorn particle will deposit in the lung, with 5 microns and less penetrating the deep lung. Above 100 microns particles are regarded as non respirable. If you can see the dust aerosol, as you often can at a chalky climbing wall, it is well above 100 microns and not inhalable. A bit may get stuck up your nose, but that's about it.

This is basically correct, however I would add that any analysis of a fine powder such as climbing chalk would show a bell curve that reveals a fraction of the powder in the respirable range. If you continue to inhale this over a long period of time there is a small risk of a silicosis / pneumoconiosis type respiratory illness which would obviously be exacerbated through smoking (widely regarded as being responsible for synergystic effects with respiratory diseases).

As a climber, walker and Safety Professional I have always wondered why indoor bouldering and climbing walls are not routinely fitted with extraction systems. These systems need not be expensive as you only really need to create an airflow through the area to remove particles in the sub 10 micron respirable range.

On my box of chalk blocks it gives a chemical composition breakdown and has an asterisk against the silica content saying something along the lines of a crystalline silica content of over 1% is bad for your lungs (the content listed is around 0.04%)

>
Before any controls are implemented, shouldn't a risk assessment be carried out first. This is the usual way round. That said, it certainly would be intersting to know what actual exposures are like at climbing walls.

Yes, but if you carried out a risk assessment you'd definitely determine there was a "Reasonably foreseeable risk" of someone experiencing a respiratory illness/disease from exposure to the said dust (or exacerbating an existing condition - e.g. climbing wall employees) therefore your hierarchy of control would go;

In reply to Dave Garnett: yeah but guess you dont inhale enough to do any real damage. Only know from an article I read about it a while back. Had a good look but couldnt seem to find it, not sure where its at?

> (In reply to BolderLicious) its an alkali for a start as well as not being organic. It is not real chalk it is syntetic and has similar affect to smoking in that it dries and shriveles your lungs.

Smoking isn't bad for you because it dries and shrivels your lungs, it is bad for you because it fills your lungs with gunk, ccarbon monoxide and relatively high concentrations of carcinogens. Chalk does none of those things, but still has no place in the lungs. I would imagine that chalk dust is probably too large to penetrate much further than the main airways though.

The black dust from rubber (I presume),was/is a worrying blow out from the nose at two of my local walls.

Chalk - seen everywhere, breathed in, but not thought of it as a health hazard - you can eat it can't you? Never thought of the lung issue.

One other issue that I've just thought of, after lots of problems in a school here in S. Wales is asbestos. A lot of the early walls were built in refurbished old churches or industrial buildings. I wonder what recognition was made to existing asbestos when some of the early walls were put up?

> (In reply to BolderLicious)
>
> One other issue that I've just thought of, after lots of problems in a school here in S. Wales is asbestos. A lot of the early walls were built in refurbished old churches or industrial buildings. I wonder what recognition was made to existing asbestos when some of the early walls were put up?
>
> mark

There will have been a survey done on the building and any asbestos will have been sampled in the lab for type, any that isn't damaged will have been encapsulated and any that is damaged will/should have been removed.
It would be virtually impossible in a climbing centre that's been runnung for some time to take air samples, the analyst wouldn't be able to read the filters.

I have sarcoidosis which affects my lungs. Before I started going to the wall again, I asked my consultant about the potential health risks, and he was confident that it wouldn't be a problem. I've been climbing two or three times a week over the past couple of years, and been fine.

Yeah...Some walls use a kind of loose shredded rubber tile as floor padding. I do wonder, when my stuff is covered with presumably fragments of old tires, what inhalation of the smaller particles does to the wall staffs long term health.

As for chalk, I presume there would be a 'school teacher lung' link, teachers from the blackboard days inhale far more than a climber would!
[Whiteboards, same thing but the particles are just smaller...Wonder what they're made out of]

In reply to tlm: I did my dissertation in 1993 - Airbourne Particulate Pollution at an inner city Climbing Wall, ie chalk dust at the Foundry.

Jan-Mar 1993 the Foundry averaged over 300 customers per day, to give you a clue how busy that is The Works hasn't averaged 300 per day for 3 months on the trot. Based on the particle size and the COSHH Regs the concerntration of dust in the air was not a health problem. It was however enough to possibly be an irritant.

At the time the US Environmental Protection Agency held not adverse information about Magnesium Carbonate BP (as the block chalk at the time was actually called). Modern chalk is either the same old stuff (eg Moon Dust) or has additives added (eg Metolius Super Chalk). I have no idea if the additives have any worrying constituents.

Interestingly chalk balls may be more of an issue as they produce a finer dust that could penetrate the smaller vessels in the lungs (the avioli?) but generally produce less dust than block chalk. As an aside any wall that claims loose chalk should be banned because of the health risk is IMHO talking bollocks

Hmm, not sure I understand your logic there. If sub 5 micron particles can move freely on air currents and successfully avoid all the defence mechanisms in your respiratory system (ciliated hair like cells, mucus lining, sharp bends/corners in the bronchi to increase the chance of impacts etc.) because they are so aerodynamic then why would the LEV system need to be large??

If you were trying to rid the air of sub 100 micron particles then I'd agree.

In reply to needvert: http://www.guardian.co.uk/education/2011/nov/28/chalk-dust-health-research
"Though real-time airborne chalk dust generation was found to be low in this study … and did not contain toxic materials, chalk dust could be harmful to allergic persons and may cause lacrimation and breathing troubles in the long run and certainly is a constant nuisance in classrooms as it may soil clothes, body parts, audiovisual aids and study materials."

perhaps I wasn't clear enough as I didn't mention LEV I mentioned an extraction system and all I meant by that was fans to move air in and out of the building (dilution ventilation) and that is all that is required to remove enough sub 5 micron particles to reduce the risk to insignificant for a normal healthy person.

2. Chronic (long term) health risks associated with respirable dust [HSE term] (typically taken as the PM10 fraction of inhalable dust). The finer PM2.5 fraction is typically thought to be of most concern.

3. Chronic health risks associated with substances in the PM10 fraction, which would include substances in climbing chalk (primarily MgCO3)

There is a legal duty (Health & Safety at Work Act etc) on employers to protect the health safety and welfare of workers and the public (which would include wall users).

The main workplace H&S regulation (relevant for workers at a business such as a wall) that covers dust is COSHH (Control of Substances Hazardous to Health Regulations), which uses a set of legally binding Workplace Exposure Limits (WELs) laid out in EH40 (most recently updated in 2011):

EH40 also contains a number of dust WELs for specified substances, but not currently MgCO3(though CaCaO3 is listed and uses the same 10 & 4 mg/m³ WELs). There are also 5 WELs for different types of silica/silicon dust. Although there is a WEL for 'rubber process dust', this does not apply to dusts arising from the abrasion of cured rubber and the general dusts WELs should be adopted for dust containing abraded rubber.

It wouldn't be best practice to automatically adopt WELS for users of the wall (essentially an 'involuntary risk' to a member of the public) and this would be a good topic of discussion with the HSE and Health Protection Agency (HPA). My view is that it would probably require a separate assessment to demonstrate acceptable risk to users, given the lower level of acceptable risk typically afforded to the public, compared with workers. For example, the UK PM10 air quality standard is 0.05 mg/m3 (2 orders of magnitude lower than the WEL)

However, if the wall levels are below EH40 levels, then I'd be surprised if a typical user would be at unacceptable risk (from a HPA standpoint, not a climbers world view) given the relatively limited exposure time for most wall users. Wall rats 'may' be a different issue (again, from a HPA standpoint).